The present invention relates generally to a method of adjusting a pick-up coil of a motor vehicle distributor and a guide tool, and more particularly to a method of centering a magnetic ring of a pick-up coil in a General Motors-type motor vehicle distributor and a centering guide tool used in the method.
A pick-up coil of a motor vehicle distributor, such as a General Motors-type distributor, is a ring-like structure which is removably secured concentrically with the distributor drive shaft within the distributor housing. The pick-up coil comprises an adjustably mounted ring-like magnet having a plurality of spaced teeth or "points" extending radially inwardly toward the axis of the distributor drive shaft. A rotor element concentrically mounted on the distributor drive shaft has a plurality of spaced projections extending radially outwardly toward the magnetic ring. The tips of the "points" of the magnetic ring must lie on the circumference of a circle which is concentric with the axis of the distributor drive shaft, and the circle must have a slightly larger diameter than the outer diameter of the rotor element so that the projections on the rotor element do not contact the magnetic ring and damage the pick-up coil. The magnetic ring is movable transversely in the pick-up coil so that the magnetic ring can be mounted concentrically with the rotor element and distributor drive shaft. When replacing a pick-up coil in a distributor, the magnetic ring of the pick-up coil when initially mounted in a distributor frequently does not align perfectly with the rotor element of the distributor shaft due to variations in the dimensions of the replacement pick-up coil or wear in the bearings of the distributor shaft.
The present method of centering the magnetic ring of a pick-up coil relative to the rotor element in a General Motors-type distributor is essentially by the trial and error "feel" method which requires repeatedly adjusting the magnetic ring in the pick-up coil until the rotor can be freely rotated without contacting any of the "points" of the magnetic ring, a process which can take a great deal of time. When the pick-up coil has a cover plate which prevents the mechanic seeing the magnetic ring and rotor element, the centering process is especially time consuming.